An examination with optical microscopy, for example, with light microscopy as well as with particle beam microscopy, for example, with electron microscopy, is often desirable, in particular for biological or material-science specimens. In the state of the art, complex microscopes which can carry out both types of microscopy methods are used. Such a microscope is known, for example, from EP 0849765 A2 or the U.S. Pat. No. 6,683,316 B2. Such combination microscopes are especially complex because the optical microscope must be completely incorporated in the vacuum chamber which is required for the particle beam microscope, and a specimen stage must be provided which moves the specimen between the two microscopes in the vacuum. The result is a relatively large vacuum volume and, moreover, considerable complexity in the production of the optical microscope which must be manufactured in a vacuum-compatible construction. A further disadvantage is that an optical imaging with immersion is not possible in the vacuum. If one forgoes the arrangement of the object in the vacuum in particle beam microscopy, as for example in the combination microscope according to United States patent application publication 2008/0030873 A1, the image quality will suffer because the electrons are scattered by a membrane as well as by the air.
An alternative to the use of such combination microscopes is the sequential use of individual devices. In the state of the art, various, incompatible bracket concepts are used for this purpose. For optical microscopy, glass slides are typically used with cover glasses which are several centimeters in size and are placed over the specimen. In electronic microscopy, nets which are several millimeters in size or metallic specimen trays are commonly used. In order to transport an object to be examined microscopically, for example, a biological specimen, from the optical microscope to the particle beam microscope, the specimen must be transferred from one support system to the other. This entails several disadvantages. First, the transfer is time-consuming and involves the danger of that the specimen will be damaged or destroyed. Further, the position referencing in both microscopy methods is difficult because the position of a region examined, for example, with optical microscopy must first be re-located for the particle beam microscopy. Even the use of markers in the object or on the biological specimen does not help here, because the specimen structure generally changes during transfer, for example, resulting from strain. A time-consuming and tedious relocating of the region previously examined with the other microscopy procedure is thus unavoidable. Even the finder grids known from transmission electron microscopy, that is round specimen nets whose net grid quadrants are marked, for example, numbered, do not solve this problem, because it is practically impossible to transfer a finder grid between two microscope platforms in the exact orientation. The position-precise recognition of a particular specimen region on the finder grid with a second microscope platform is thus hardly possible.
From DE 10 2009 020663, the content of which is incorporated by reference, a specimen slide system is known with which the objects can be microscopically examined one after the other with optical microscopy and particle beam microscopy. The system includes a holder having a window which is configured to be placed in a particle beam microscope as well as an optical microscope and a specimen slide element which can be placed over the window of the holder, whereby the specimen holder element can be fixed over the window. For the position-precise detection of a particular specimen region during the sequential implementation of different microscopy platforms alignment marks are suggested which make it possible to bring a particular object region into a desired position in each microscope, in that calibration of the object region in relation to the position of the holder is effected by the alignment marks.
In DE 10 2009 020663, the alignment marks are arranged as structures on the non-transparent holder, which fact has the disadvantage that the holder surface must be manufactured with a low surface roughness which makes the surface very scratch-sensitive. As a result of the scratch sensitivity, the holder may quickly become unusable if the mark gets damaged. Furthermore, an applied mark is very low-contrast under a stereo microscope, which fact makes the automatic calibration almost impossible. The risk of soiling is very high with applied marks. Such fine structures cannot be cleaned in an ultrasonic bath either, which makes it very difficult to automatically calibrate the mark, in particular, in the electron microscope. All these problems in connection with applied marks make the re-use of the holder almost impossible in different microscopy methods and specimens. A further disadvantage is that when the alignment marks are arranged on the non-transparent holder as structures, the position of the mark can only be seen from one side of the holder. A precise position determination from both the top and the bottom of the holder is, however, important if both microscopy methods access the specimen from different sides and the same specimen region is supposed to be detected at a precise position.